JP2002116238A - Ic socket and method for detecting contact failure in the same - Google Patents

Abstract

PROBLEM TO BE SOLVED: To detect the presence or absence of contact failure between the contact pins of an IC socket and the lead pins of an IC with the IC mounted. SOLUTION: Probes P1-P6 for tests are inserted through the pressing lid of the IC socket in such a way as to be each in contact with the lead pins of the surface-mounting-type IC 10 placed on a seating 14. A voltage for tests is impressed on all of the probes P1-P6 for tests from a ring-shaped electrode L1. The lead pins of the IC are connected to a gate circuit 16 for tests via the contact pins Q1-Q6. Then the potential change of each lead pin is determined by the gate circuit 16 for tests, and the results of the determination are announce by the lightening of a light emitting element 18.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to an IC socket and a method for detecting a contact failure in the IC socket.

[0002]

2. Description of the Related Art An IC socket includes a pedestal for mounting an IC, a holding lid, and a plurality of contact pins which individually contact the respective leads of the IC and extend to the outside through the pedestal. It has a structure to do.

[0003] In an IC socket, a plurality of contact pins, which press the IC (package and each lead pin) with a pressing lid to ensure electrical contact between each lead pin and the contact pin, are supplied to an inspection device or the like. By electrically connecting and transmitting and receiving signals between the IC and the inspection device, an operation test and the like of the IC are performed.

[0004]

An IC socket is required to have an electrical and mechanical structure that can withstand repeated use as much as possible. However, when the number of times of testing of the IC increases, the risk of poor contact occurring mainly at the portion of the contact pin that comes into contact with the IC lead increases due to fatigue phenomena due to repeated stress, wear and deformation of the contact portion, and the like.

[0005] It is assumed that some trouble occurs when the IC socket is connected to the IC socket and the IC is analyzed. At this time, it cannot be determined whether the cause is a poor contact between the IC and the IC socket or a problem on a test board on which the IC socket is mounted.

For this reason, there is a case where the IC itself is erroneously determined to be a defective product due to a poor contact between the contact pins of the IC socket and the leads of the IC.

The present invention has been made to solve such a conventional problem, and makes it possible to inspect a contact state between a lead pin and a contact pin of an IC when the IC is mounted. The purpose is to:

[0008]

SUMMARY OF THE INVENTION An IC socket according to the present invention is provided for applying a voltage for contact failure inspection to all leads of an IC in addition to contact pins individually contacting each of the leads of the IC. A test probe is provided. Thereby, a test voltage can be simultaneously applied to all the lead pins of the IC via the test probe.

If the connection between each contact pin and each lead pin is all good, the contact pin should be at the same potential by the test voltage applied to each of the lead pins. Therefore, a contact failure can be detected by detecting a voltage change of the contact pin.

If the potential change of each contact pin can be individually detected, it is possible to determine which pin has a contact failure. However, since the IC has a large number of pins, the inspection circuit is complicated. Therefore, in reality, it is desirable to determine whether or not a potential change has occurred in all of the contact pins, and to determine only whether or not there is a contact failure.

If the presence of the contact failure can be confirmed, the measurement is restarted using another IC socket,
It is possible to take measures such as discarding a defective IC socket.

[0012]

Next, an embodiment of the present invention will be described with reference to the drawings.

First, an outline of a contact failure detecting mechanism (and a contact failure detection method) of an IC socket according to the present invention will be described with reference to FIG.

As shown in FIG. 1, a pedestal 1 of an IC socket
4, the IC 10 to be inspected is mounted. And IC
Are connected to the test gate circuit 16.

The test gate circuit 16 has a configuration in which two-input AND gate circuits (such as A1 to A6) are connected in series. One input terminal of each of the AND gates (such as A1 to A6) is a contact. It is connected to each lead pin (C1 to C6 etc.) of the IC 10 via a line (Q1 to Q6 etc.).

On the other hand, the test voltage supply ring L1 is connected to the IC through test voltage supply lines (P1 to P6, etc.).
10 lead pins (C1 to C6, etc.). Then, the test voltage source 12 is connected to the test voltage supply ring L.
1 and a test voltage (for example, a DC voltage of a predetermined level (H level)) is applied to each lead pin (C1
To C6).

Each contact line (Q1 to Q6, etc.)
If all the lead pins (C1 to C6, etc.) of the IC 10 are connected well, all the inputs of the AND gates A1 to A6 in the test gate circuit 16 become high level (H level). Therefore, the output of the test gate circuit 16 becomes a high level (H level).

Therefore, the light emitting diode 18 serving as a notification element is turned on to notify the user that there is no contact failure in the IC socket.

On the other hand, if a contact failure occurs in the IC socket, the output of the test gate circuit 16 becomes low level (L level), and the light emitting diode 18 does not turn on. Thus, occurrence of a contact failure in the IC socket is detected. In this case, the user will have a new I
In addition to using the C socket, it is possible to quickly take measures such as discarding the socket having a poor contact. Thus, the efficiency of the IC testing operation is improved.

Next, an example of a specific structure of the IC socket used in the present invention will be described with reference to FIG.

Referring to FIG. 2, the IC socket 70 includes the pedestal portion 20 and the holding lid 30. The presser lid 30 is configured to rotate around the fulcrum 33 and to be openable and closable.

The locking member 32 is provided with the holding lid 30 in a closed state.
And the pedestal 20. That is, the claw X1 of the locking member 32 is notched by the notch Y provided on the side of the pedestal.
As a result, the presser lid 30 and the pedestal portion 20 are fixed.

The holding lid 30 has a surface mount type I
Test probe pins (50a to 50b, etc.) are provided at positions corresponding to the lead pins (C1, C2, etc.) of C10. Test probe pins (50a-50b
) Are drawn upward through the presser lid 30. The portion led out on the holding lid 30 serves as test voltage supply electrodes (S1, S2, etc.).

The test probe pins (50a, 50
b) in the state where the presser lid 30 is closed.
It comes into contact with a part of the lead pins (C1, C2, etc.) of the IC 10. The tip portion of the test probe pin is formed as a rounded protrusion like a bump electrode, for example, so that the structure can be made extremely resistant to mechanical stress.

The surface mount type IC 10 is mounted on the pedestal 20. Each lead of IC10 (C1, C2, etc.)
Are the contact pins (40
a, 40b, etc.). Contact pin (40
a, 40b, etc.) penetrate the pedestal portion 20 and are led out downward, and the portion protruding to the outside functions as an external connection terminal.

Next, a mechanism for detecting the presence or absence of a contact failure in an IC socket and a method thereof will be described in detail with reference to FIG.

The IC socket 70 has a surface mount type I
C10 is mounted. The presser lid 30 is in a closed state. The IC 10 is pressed by the holding lid 30. As a result, each of the lead pins (C1, C2, etc.) is brought into contact pin (40a, 4
0b). However, poor contact may occur due to deformation of the pin due to repeated attachment and detachment of the IC.

On the other hand, the tips of the test probe pins (50a, 50b, etc.) provided through the holding lid 30
In the figure, a portion A surrounded by a dotted line is connected to each lead pin (C1, C2, etc.) of the IC 10.

Next, contact pins (40a, 40b, etc.) projecting downward from the IC socket are connected to a test gate circuit 16 provided on an inspection board (or another substrate) 100. As described in FIG. 1, the test gate circuit 16 includes an AND gate (A) connected in series.
1, A2, etc.) and a light emitting diode 18 as a notification element.

Next, a ring-shaped electrode 60 (corresponding to L1 in FIG. 1) and a plurality of power supply electrodes (S1 to S6, etc.) provided above A test voltage supply electrode composed of pins (P1 to P6, etc.) is connected. Then, the test voltage source 12 is connected to the ring-shaped electrode 60, and a test voltage (for example, a DC voltage of about 3 V) is applied.

At this time, each lead pin (C
1, C2, etc.) and the contact pins 40a, 40b are all electrically connected, the test gate circuit 16
The input of each AND gate (A1, A2, etc.) at
All become high level (H level). Therefore, the output of the test gate circuit 16 becomes a high level (H level).

Accordingly, the light emitting diode 18 serving as a notification element is turned on to notify the user that there is no contact failure in the IC socket 70.

On the other hand, if a contact failure occurs in the IC socket 70, the output of the test gate circuit 16 becomes low level (L level), and the light emitting diode 18 does not turn on. Thus, occurrence of a contact failure in the IC socket is detected. In this case, the user can quickly take measures such as using a new IC socket and discarding the socket having poor contact. Thus, the efficiency of the IC testing operation is improved.

FIG. 4 summarizes the procedure of the contact failure detecting method for the IC socket described above.

First, the IC to be inspected is mounted on the IC socket, and the holding lid is locked on the base. Thus, each probe pin is brought into contact with the corresponding IC lead pin (step 100).

Next, a test gate circuit is connected to the contact pins of the IC tester (step 102). next,
A test voltage is simultaneously supplied to each probe pin of the IC via a test voltage supply electrode (ring) (step 104).

Based on the output of the test gate circuit, it is determined whether or not there is a contact failure between the IC lead pin and the contact pin inside the IC socket (step 106).

[0038]

As described above, according to the present invention, I
A test probe is installed in the C socket, and a test voltage is applied from this test probe to all pins of the IC.
By determining the output of the inspection circuit, it is possible to determine the presence or absence of a contact failure inside the IC socket.

This eliminates the need to measure the contact failure between the lead pin and the contact pin one pin at a time at the time of mounting the IC, thereby making the mounting inspection more efficient.

[Brief description of the drawings]

FIG. 1 is a diagram for explaining an overall configuration of a contact failure detection mechanism (and a contact failure detection method) in an IC socket of the present invention.

FIG. 2 is a sectional view showing the structure of the IC socket of the present invention.

FIG. 3 is a diagram showing a structure of a contact failure detection mechanism in the IC socket of the present invention.

FIG. 4 is a flowchart showing a procedure of a contact failure detection method in an IC socket of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 IC 12 Test voltage source 14 Base of IC socket 16 Test gate circuit 18 Light emitting diode (notifying element) L1 Test voltage supply line A1 to A6 AND gate

Claims (4)

[Claims] 1. A test probe pin for applying a voltage for contact failure inspection to all leads of an IC, in addition to a contact pin individually contacting each of the leads of the IC. IC socket. 2. A plurality of contact pins individually contacting each of the lead pins of the IC and being pulled out through the pedestal on which the IC is mounted, and the IC mounted on the pedestal, And a plurality of test probe pins which individually contact the respective leads of the IC and which are pulled out to the outside through the presser lid. . 3. A plurality of contact pins which individually abut against each of the lead pins of the IC and which are drawn out through the pedestal on which the IC is mounted, and the IC mounted on the pedestal, An IC socket comprising: a presser lid for pressing from a direction opposite to the above; and a plurality of test probe pins that individually contact the respective leads of the IC and pass through the presser lid and are drawn out to the outside. A power supply electrode for commonly applying a predetermined voltage to each of the test probe pins pulled out through the presser lid; and a plurality of input AND gates connected in series, and the base of the IC socket. Each of the plurality of contact pins that are pulled out therethrough is electrically connected to the corresponding input terminal of the AND gate. And a notifying circuit for receiving a signal output from the gate circuit and notifying the presence or absence of a contact failure in the IC socket. Contact failure detection mechanism in IC socket. 4. A method according to claim 1, further comprising the step of: a plurality of contact pins individually contacting each of the lead pins of the IC and being pulled out through the pedestal on which the IC is mounted, and the IC mounted on the pedestal. A presser lid pressed from a direction opposite to the above, and an IC socket having a plurality of test probes which individually contact the respective leads of the IC and which are drawn out to the outside through the presser lid,
C, mounting the holding lid on the pedestal while the IC is pressed by the holding lid, connecting a plurality of input AND gates in series, and penetrating the pedestal of the IC socket. Each of the plurality of contact pins pulled out as above is electrically connected to an input terminal of the corresponding AND gate, and receives a signal output from the gate circuit, Electrically contacting each of the contact pins of the IC socket with a contact failure inspection circuit having a notification circuit for reporting the presence or absence of a contact failure in the IC socket; and Applying a predetermined voltage in common to each of the test probes drawn out, and the notification of the contact failure inspection circuit. Defect detection method contacts in an IC socket, characterized in that to determine the presence or absence of contact failure by the information output from the road.